There are cases where you might want a GroupBox for grouping a set of child controls, but without the visual border around the controls. You can retain the header element, but remove the border of a GrouBox by setting the BorderBrush property to Transparent.

You can use the Thumb control to allow dragging a control around on a parent Canvas. To make it a little more obvious to the user that the control can be dragged, you can set up a Border around the control that only shows up when the user moves the mouse over the control.

If you want to clip against the Border, you can specify an opacity mask that is a visual brush bound to the visual of a second Border element that overlays the Image control. This will cause any portion of the Image control that falls outside the boundaries of the inner Border to use an opacity of 0.0.